Process for converting hydrocarbons



Dec. 13, 1932. Q DUBBS 1,890,974

PROCESS FOR CONVERTING HYDROGARBONS Original Filed May 25, 1921 Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE CARBON P. DUBBS, OF WILMETTE, ILLINOIS, ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS FOR CONVERTING HYDROCARIBONS Continuation of application Serial No. 411,619, filed May 28, 1921.

This application filed February 15, 1926.

Serial No. 88,501.

This application is a continuation of my (o-pending application, Serial No. 471,619, filed May 23, 1921. This invention relates to improvements in process and apparatus for converting hydrocarbons and refers more particularly to a process for rerunning the distillate through the dephlegmator, thereby producing increased refinement and more uniform dephlegmating conditions.

Among the salient objects of the invention are to provide a process for the conversion of hydrocarbons from oils of a relatively high boiling point to liquid distillate of a substantially lower boiling point in which the oil, after conversion in the reacting zone, is separated into an unvaporized and a vaporized portion, the vaporized portion passed through dephlegmating and condensing stages; to provide a process in which the distillate produced from the vaporized portion is redirected to the dephlegmating stage and there used as a dephlegmating medium in combination with the raw oil; to provide a process whereby a more complete refinement may be effected by the returning and rerunning of the distillate through the dephlegmater and one in which besides being of higher quality, the distillate is also of a more uniform character; to provide an apparatus for carrying out this process and in general to provide a process and apparatus of the char acter referred to.

The single figure is a side elevational view of the apparatus with parts in section.

Referring in detail to the drawing, the raw oil is introduced from any convenient source through the inlet pipe 1 into the dephlegmator 2, the inlet pipe extending well down into the dephlegmator, thereby avoiding the undesirable condition of having some of the lighter cuts of the raw oil immediately separated and passing over into the receiver. The raw oil serves as a dephlegmating medium, passing in opposed direction tothe vapors which rise through the dephlegmating column. The raw oil together with what condensate it may collect in coming in contact with the vaporized oil, is drawn off from the bottom of the dephlegmator through the line 3 controlled by a valve 4. The oil is charged by means of the pump 5 through the line 6 controlled by valve 7 to the heating coil 8 mounted in a furnace 9 WlllChiS preferably heated by means of gas burners 10. The oil, after being raised to a cracking temperature in the heating coil, passes to the transfer line 11 to the vaporizing or reacting chamber 12. From this stage, the vapors pass off through the line 13 to the dephlegmator 2 while the unvaporized portion is drawn ofi' intermittently or continuously through the residuum line 14 controlled by valve 14*. The vaporized portion passes through the dephlegmating or rectifying column, and is refluxed by the raw oil flowing in an opposed direction. A drawoif line 15 directs the vapors from the dephlegmator to a water condenser 16 where they are reduced to liquid distillate and collected in the receiving tank 17 through the line 18 regulated by valve 19. The receiver has a l'quid drawofi' line 20 regulated by the valve 21, pressure relief pipe 22, controlled by a valve 23. From the receiver, the distillate may be returned through the pump 24 and line 25 to the top of the dephlegmator where it may be introduced to the charging line 1 through the valve 26 or may be charged directly into the top of the dephlegmator through the valve 27. By thus returning the distillate and introducing it to the dephlegmating stage in either manner, it is utilized as a dephlegmating medium and intimately contacting with the heated vapors is subjected to additional conversion, thus producing a more refined product which is finally collected in the receiver. By regulating the quantity of distillate that is returned in this manner,

the temperature in the top of the dephlegma- .tor may be accurately controlled, this temstage and somewhat remote from the vapor line to the condenser, there is less of these heavy or extremely light cuts separated from the raw oil and carried over and very little of the dephlegmating efi'ect of the raw oil is lost. A further advantage of returning the distillate and introducing it with the raw oil is that the 'heat of the distillate somewhat tempers the incoming oil charge and besides thoroughly rectifying the return distillate. This simple distillate return alone will also decrease materially the amount of apparatus which is necessitated to further refine or rectify the distillate from the receiver.

I claim as my invention:

1. A process for cracking hydrocarbon oil, consisting in raising the oil to a cracking temperature in a heating zone, in passing vapors evolved from the oil to a dephlegmator, in condensing the dephlegmated vapors issuing from said dephlegmator, in collecting the resulting distillate, in controlling the percentage of vapors condensed in said dephlegmator by introducing a regulated quantity of said distillate to the dephlegmator adjacent the vapor outlet therefrom and by introducing regulated quantities of incoming charging oil to said dephle mator at a point well below the vapor disc arge therefrom, and in maintaining a superatmospheric pressure on the oil undergoing conversion in the process.

2. A method of distillin hydrocarbon oil for the formation of low boiling products, which consists in heating such oil under pressure to a conversion temperature, introducing into the vapors evolved by the oil, liquid hydrocarbon oil having approximately the characteristics of the desired products, removing the vapors of the desired products together with the vapors of the oil introduced and returning to the oil undergoing heating condensed products of a higher boiling point than the desired products.

3. A method of distilling hydrocarbon oil for the formation of low-boiling products which consists in heating such oil under pressure to a conversion temperature, introducing into the vapors evolved by the oil, a. liquid hydrocarbon oil substantially identical with the desired low-boiling products evolved from the still and previously produced therein, removing the vapors of the desired products, together with the vapors of the oil introduced and returning to the oil undergoing heating condensed products of a higher boiling point than the desired loW- boiling product.

4. A process for cracking hydrocarbon oil, consisting in raising the oil to a cracking temperature in a heating zone, in passing vapors evolved from the oil to a dephlegmator, in condensing the dephlegmated vapors issuing from said dephlegmator, in,col1ectin the resulting distillate, in controlling t e percentage of vapors condensed in said dephlegthe process.

CARBON P. DUBBS. 

